Hi everyone,
hopefully the last iteration of those patches.
For now I've addressed the issue of unmapping imported BOs from the amdgpu page tables immediately by locking the page tables in place.
For HMM handling we are getting the ability to invalidate BOs without locking the VM anyway, so this last TODO will probably go away rather soon.
Place comment,
Christian.
I don't totally understand the stack trace but I do see a double free
bug.
drivers/gpu/drm/vgem/vgem_drv.c
186 static struct drm_gem_object *vgem_gem_create(struct drm_device *dev,
187 struct drm_file *file,
188 unsigned int *handle,
189 unsigned long size)
190 {
191 struct drm_vgem_gem_object *obj;
192 int ret;
193
194 obj = __vgem_gem_create(dev, size);
obj->base.handle_count is zero.
195 if (IS_ERR(obj))
196 return ERR_CAST(obj);
197
198 ret = drm_gem_handle_create(file, &obj->base, handle);
We bump it +1 and then the error handling calls
drm_gem_object_handle_put_unlocked(obj);
which calls drm_gem_object_put_unlocked(); which frees obj.
199 drm_gem_object_put_unlocked(&obj->base);
So this is a double free. Could someone check my thinking and send
a patch? It's just a one liner. Otherwise I can send it on Monday.
200 if (ret)
201 return ERR_PTR(ret);
202
203 return &obj->base;
204 }
regards,
dan carpenter